Dentist s chair



NUNITED sfrnrus Param* OFFICE.

A. M. ASAY, OF' PHILADELPHIA, PENNSYLVANIA,

DENTISTS CHAIR.

Specication of Letters Patent No. 7,299, dated April 23, 1850.

To all 'wh-0m t may concern.'

Be it known that I, ABRAHAM MERRITT AsAY, of the city and county of Philadelphia and State of Pennsylvania, have invented a new and Improved Method of Elevating the Seat of a Dentists or other Chair; and I do hereby declare that the following is a full and exact description.

The nature of my invention consists in constructing a deep bottom or seat to a common arm chair, consisting of an external box, Figure l, in which is the following machinery, to wit; a wheel cogged on the upper surface and periphery Fig. 1, working on an axle B Fig. 1, aixed to the bed or under part of the box C, C, Fig. 1 more fully represented in Fig. 2, which is an upper view of the same wheel of which a side. view is only given` in' Fig. 1. Said wheel is used to turn 2, 3, or 4 male screws (at the pleasure of the maker, but the draw ings are made with 4 screws, it being be lieved that that number acts more steadily and with less friction) which screws A1, and B1, Fig. 5, are furnished with smaller cog wheels, A2, B2, C2, and D2 Fig. 2, at the lower end, working into the cogs of the above mentioned larger wheel A, Fig. 1, and into 2, 3 or 4 female screws A3, B3, C3, and D3, Fig. 4 and running up into pipes A4, B4, C4, and D, Fig. 3 in the seat or inner box F Fig. 1, intended to be elevated, the whole of which is moved by a winch D Fig. 1, on which is a cogged wheel, E Fig. 1, working into the cogs on the upper side of the larger wheel A Fig. 1, and upon the winch D Fig. 1, being turned toward the left side of the chair, the seat rises, according to the length of the screws, from 7 to 12 or even 20 inches.

To enable others skilled in the art to make and use my invention I will proceed to describe more particularly, the machinery used in the elevation of the seat and its opera tion.

The chair is constructed in the usual way, except that the front, side, and back pieces A5 and B5 Fig. 7 must be 8 inches or more in width, according to the length of the screws A1 and B1 Fig. 5; at the bottom of these pieces is secured a strong bed piece of inch board C5, Fig. 5 extending under the whole of the seat and forming the external box, which has let into it 5 iron or brass sockets, in their respective places, to receive the lower end of the axle of the large cog wheel A Fig. l, and those of the smaller cog wheels A2, B2, C2, and D2, Fig. 2.; which axles being prolonged upward, work, say B Fig. 1 in a collar or socket of brass or iron A, Fig. 6, inserted in the center of another piece of board C6 Fig. 6, and the other axles being prolonged into screws A B Fig. 5, pass through similar collars or sockets B7 C, D, E Fig. 6 so as to work in the female screws A3, B1, C3, D3, Fig. 4 or nuts which are affixed as will be seen on reference to the drawings accompanying this speciication, to the bottom I of the seat Fig. 4 or inner box F and passing through said screws or nuts A3, B3, C3, D3 Fig. 4 into pipes z' i Figs. 3 and 7 on the inside of the seat, the tops or` covers of which pipes are seen at A4, B4, C4, and D1 Fig. 3, which Fig. 3 exhibits an upper view of the inner box, which will have on it the usual stuffed cushion to form the seat. Fig. 6 representing a strong board into which the above mentioned sockets A B", C, D.I E are inserted and which also has in it an aperture or opening through which works the upper cog wheel E Fig. 1 whose axle is conned on the upper side of Fig. 6 by means of 2 collars or boxes G and H Fig. 6 and being prolonged back forms a part of the winch D Fig. 1. Fig. 6 is let down on to two projections D5 and E5 Fig. 5 to which it is also confined by wood screws.

The larger cog wheel A Fig. 1 asv aforementioned is cogged on its upper side and circumference the upper side F Fig. 5 being beveled, and the circumference A Fig. 5 being perpendicular and into which work the cog wheels of the male screws. On the beveled or upper edge F Fig. 5 of the cog wheel A Fig. 2 works the cog wheel E Fig. 1 connected as already mentioned with the winch D Fig. 1 which puts the whole in motion as already stated.

Having described the nature of my invention and improvement what I claim and desire to have secured to me by Letters Patent 1s- The manner in which I arrange the operating parts within the frame work and under the seat in combination with the seat so January in the year of our Lord, one thoun made as to move up and down Within the sand eight hundred and forty nine (1849). 1U

frame Work and a ear like an entire seat- Y as herein set forthpp A MERRITT ASAY' [Lf S] 5 In testimony thereof I, ABRAHAM MER- Signed in presence of us as attesting Wit- RITT ASAY, do to these presents, in the presnesses: ence of the underwritten attesting Witnesses, ELIJAH M. NEALL,

aix my signature this thirty-first day of ED. SPRAGUE. 

